This application claims the priority of German patent document 102008033235.6-56, filed Jul. 15, 2008, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a method for automatically determining a landing runway for an aircraft.
It is a frequent occurrence that airplanes approach the wrong landing runway at an airport. This happens not only when the visibility is poor but frequently also when there is good visibility. In some cases, although airplanes approach the correct landing runway, they do so from the wrong direction. Both situations (approaching the wrong landing runway and approaching the correct landing runway from the wrong direction) may result in dangerous situations, particularly in the case of airports with high air traffic density.
Published U.S. Patent Application No. 2007/0142982 A1 discloses a method for determining the touch-down spot of an airplane on a landing runway. In this case, the touch-down point is calculated based on information concerning the situation in the airplane and the intentions of the crew, and based also on information concerning the configuration of the landing runway. For this purpose, a computer onboard an airplane correlates these two types of information in order to determine the runway on which the airplane is to land, and particularly the touch-down point of the airplane thereon. Although this method permits the determination of the correct landing runway, it cannot prevent an airplane from approaching the landing runway from the wrong direction. Therefore, certain dangerous situations cannot be prevented because air space intended for an approach to a different landing runway can be used by the airplane for approaching the landing runway.
It is therefore an object of the present invention to provide a method for automatically determining a landing runway which, in particular, can help to avoiding dangerous situations in the air space.
This and other objects and advantages are achieved by the method according to the invention, in which the prediction of the touch-down point of an airplane on the landing runway according to Published U.S. Patent Application No. 2007/0142982 A1 is no longer used to determine the landing runway. Rather, the spatial deviation of the aircraft relative to several control points along the landing approach suitable (and open) for the weather situation and prediction of the touch-down point, are used for this purpose. In this manner, it can be assured not only that the correct landing runway will be used, but also that the flight to the landing runway takes place along the correct path, thereby further improving the safety of the landing approach, especially in the case of high-traffic airports.
One embodiment of the invention provides a method having the following steps:                determining control points assigned to a landing runway along a landing approach of an airplane,        determining the spatial deviation of the airplane from the determined control points,        determining an appropriate landing runway, taking into account the determined spatial deviation; and        causing the airplane to land on the determined landing runway.By identifying the control points and the spatial deviation of the airplane from them, the position of the airplane can be determined automatically with respect to a landing runway to which the control points are assigned. In this case, the control points, in principle, define the correct approach path of a landing runway. This, in turn, permits the automatic determination of an appropriate landing runway, because it can be determined rapidly how the airplane is positioned relative to the landing runway, including in particular the direction from which it is approaching the landing runway. Here, an appropriate landing runway is the one landing runway that is approached from the correct direction.        
According to an embodiment of the invention, the determination of the spatial deviation of the airplane from the determined control points may include an evaluation of the meeting of the control points, using one or more of the following parameters: location, speed, angle of approach and vertical rate of descent of the airplane. A certain location in the form of coordinates in three-dimensional space may be assigned to each control point. The precision with which a control point is met can be determined by comparing the actual airplane coordinates with the coordinates assigned to the control point. In addition, further parameters, such as an optimal airplane speed, an optimal angle of approach and an optimal vertical descent may be assigned to a control point. All these parameters may also be compared with the actual flight data of the airplane in order to determine the precision with which a control point has been “met” by an approaching airplane.
According to an another feature of the invention, as the distance to a landing runway decreases, the control points can be set at increasingly shorter distances, so that the evaluation of the meeting of the control points can be carried out with increasing precision. As a result, determination of a suitable landing runway can be intensified mainly in direct proximity of the landing runway, so as to be able to determine as reliably as possible in this critical and accident-endangered zone, whether the correct landing runway is approached from the correct direction.
Furthermore, according to still another feature of an embodiment of the invention, the determination of an appropriate landing runway, taking into account the determined spatial deviation, may further comprise the evaluation of landing approach paths three-dimensionally stored in a databank, with the selection of an appropriate landing runway being made as a function thereof. For example, by means of the determined spatial deviation, an appropriate landing approach path can be determined, stored in the databank, and indicated to a pilot in a display, whereby the determination of an appropriate landing runway can be significantly simplified for the pilot.
In addition, user input can also be taken into account when selecting a suitable landing runway. For example, different landing runways appropriate for an airplane during a landing approach may be offered for selection by the pilot, who can then chose a landing runway.
The invention also includes a computer program for the implementation of the method according to the invention, as well as a computer program product, which comprises a machine-readable program carrier on which a computer program according to the invention is stored in the form of electronically and/or optically readable control signals.
Finally, the invention provides a device for automatically determining a landing runway, which device is equipped for implementing the method according to the invention as described above, and is constructed for operation in an airplane. The device may be constructed, for example, as an independent unit to be used in the cockpit of an airplane. The unit may also be constructed as a mobile device; and a special purpose computer is conceivable, which can be carried along comfortably in the airplane by the flight crew. As an alternative, the device may also be fixedly installed in the cockpit of an airplane in order to thereby ensure improved safety, particularly for the critical landing approach.
In particular, according to an embodiment of the invention, the device may be constructed to receive signals of control points for example, via corresponding receiving devices, such as optical or radio receivers.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.